Boric acid occurs naturally in the environment. Natural sources include sea-salt aerosols, soil dusts, volcanoes, biomass burning (for example, forest fires), plant aerosols, and rock and soil weathering.
Boric acid is an essential micronutrient for the growth of plants and an essential element for other organisms, such as fish and frogs. Currently, information on whether boric acid is an essential nutrient for humans is inconclusive.
How are they used?
In Canada, boric acid, its salts and its precursors are used in a wide variety of products and applications. These include fibreglass and cellulose insulation, fertilizers, metallurgical, oil and gas extraction and surface finishing. They are also found in pesticides, cleaning products, cosmetics, drugs and natural health products, swimming pool and spa chemicals, gypsum boards and engineered wood products.
These substances are used to manufacture pulp and paper products, rubber, paints and coatings, plastics and chemicals (such as lubricants and flame retardants).
Based on the most recent data, these substances are imported into the country in large quantities.
Why is the Government of Canada assessing them?
Boric acid, its salts and precursors were considered as part of the Substance Groupings Initiative. These substances were included for the screening assessment based on their potential risks to the environment and to human health.
A number of substances included in the assessment of boric acid, its salts and its precursors were identified as priorities for assessment based on the categorization of substances within the Domestic Substances List (DSL).
How are Canadians exposed to them?
The general population is primarily exposed to boric acid, its salts and its precursors naturally through food (such as, fruits and vegetables) and drinking water.
Canadians may also be exposed to boric acid through the use of commonly used products available to consumers such as pesticides; cleaning products; cosmetics; drugs and natural health products; and swimming pool and spa products.
Exposure may also occur from home-made arts and crafts materials, and toys (for example, slimes, doughs, putties) made using borax (as boric acid).
How are they released to the environment?
Although found naturally in the environment, boric acid, its salts and its precursors may also be released as a result of its use in applications (for example, fibreglass insulation manufacturing, metal surface finishing). It may be formed as a by-product during industrial activities such as coal-fired power generation, metal extraction and processing, oil and gas extraction, and waste disposal (landfill leachate).
Following releases to the environment, boric acid may enter water, air and soil.
What are the results of the assessment?
The Government of Canada has conducted a science-based evaluation, called a screening assessment, of boric acid, its salts and its precursors and thereby includes all substances containing boron that can release boric acid.
Screening assessments address the potential for harm to the general population of Canada and to the environment.
Results of the draft screening assessment indicate that boric acid, its salts and its precursors have the potential to remain in the environment for a long time, accumulate in a limited number of organisms, and cause harm to some organisms.
The Government of Canada is therefore proposing that boric acid, its salts and its precursors are entering or may enter the environment at levels that constitute a danger to the environment.
The Government of Canada is also proposing that boric acid, its salts and its precursors may be considered harmful to human health at current levels of exposure. Natural sources of boric acid in food (for example, fruits and vegetables) are not considered to be a health risk.
If the proposed conclusion is confirmed in the final screening assessment, the Government of Canada will consider options to manage releases of these substances to water to address ecological concerns, as appropriate, and address the exposure of Canadians to boric acid from certain products available to consumers.
Health Canada will review the current listing for boric acid and its salts on the Cosmetic Ingredient Hotlist which indicates concentration limits for use in cosmetic products.
For commercially available children's toys, compliance and enforcement of the existing prohibition on boron will continue as part of the regular enforcement of the Toys Regulations under the Canada Consumer Product Safety Act.
The Pest Management Regulatory Agency (PMRA) of Health Canada published a re-evaluation decision on the uses of pesticides containing boron on July 22, 2016. Certain commercial and domestic pesticide uses of boron are being cancelled due to potential health risks. More information can be found in the re-evaluation decision document.
What can Canadians do?
The health risks associated with a chemical depend on the hazard (its potential to cause health effects) and the dose (the amount of chemical to which you are exposed).
Natural sources of boric acid in food (for example, fruits and vegetables) are considered safe. Canadians should continue to eat these as part of a balanced diet according to Eating Well with Canada's Food Guide.
Additional sources of exposure to boric acid should be minimized as much as possible. For example, Canadians should avoid using borax to make arts and crafts or toys at home (for example, slime).
As a general precaution, Canadians are reminded when using any product to carefully follow any safety warnings and directions and to dispose of the products appropriately.
Canadians are also reminded to properly and safely store household chemical products, cosmetics and drugs locked out of sight and reach of children.
Canadians who may be exposed to boric acid, its salts and its precursors in the workplace should consult with their employer and occupational health and safety (OHS) representative about safe handling practices, applicable laws and requirements under OHS legislation and the Workplace Hazardous Materials Information System (WHMIS).
